New upper suggestion?

[JLeeA]

Have a 6.5 Grendel Odin 20" upper that I use on my Bushmaster(Windham built) XM15. Also have a Colt 6920 and a Daniel MK18 pistol. Wanting to get a new upper 6.5G for the Colt or Daniel for self defense but stuck on making a decision. Which way should I go? Another pistol or go with 16" ATF legal rifle on the 6920? Been looking at another Odin upper.

[FLshooter]